This application is related to and incorporates herein by reference Japanese Patent Application No. 8-343013 filed on Dec. 24, 1996 and No. 8-344776 filed on Dec. 25, 1996.
1. Field of the Invention
The present invention relates to a blow-by gas passage abnormality detecting system for detecting an abnormality in a blow-by gas passage for recirculating the blow-by gas, as will leak from the combustion chamber of an internal combustion engine to a crankcase, to the intake passage.
2. Related Art
A blow-by gas recirculating system for preventing blow-by gas from being released into the atmosphere is known in which a blow-by gas passage for recirculating the blow-by gas, as will leak from the combustion chamber of an internal combustion engine to the crankcase, to the intake passage is provided.
When an abnormality such as breakage in or detachment of the blow-by gas passage occurs, the blow-by gas may be released, contrary to the desired prevention of environmental pollution.
Thus, the present invention has an object to provide a blow-by gas passage abnormality detecting system for an internal combustion engine, as can minimize the release of the blow-by gas into the atmosphere and the adverse effect on the internal combustion engine, by detecting an abnormality in the blow-by gas passage properly.
In a blow-by gas passage abnormality detecting system for an internal combustion engine, according to a first aspect of the invention, the abnormality of the blow-by gas passage for returning the blow-by gas in the internal combustion engine to the side of the intake passage is decided on the basis of the amount of load when the running state of the internal combustion engine is idle. By thus grasping the load amount at the idling time of the internal combustion engine, the abnormality of the blow-by gas passage can be properly detected to minimize the release of the blow-by gas into the atmosphere and the adverse effect on the internal combustion engine.
In a blow-by gas passage abnormality detecting system of the internal combustion engine, according to the second aspect of the invention, the abnormality in the blow-by gas passage is decided on the basis of the pressure in the blow-by gas passage. By the simple and inexpensive construction for detecting the pressure in the blow-by gas passage, the abnormality of the blow-by gas passage can be properly detected to minimize the release of the blow-by gas into the atmosphere and the adverse effect on the internal combustion engine.